Aluminum ophobite



Patented Sept. 2, 1930 p i i UNITED STATES PWTATENT OFFICE DONALD B. BRAlDNER, F PHILADELPI EIA, PENNSYLVANIA ALUMINUM ornonrrn ,No Drawing. Application filed February 21, 1925.= Serial No. 10,982.-

(GRANTEIi UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1883', 22 STAR L, 625) The invention described herein may be used 4. Aluminum ophorite gives more heat per by the Government, or any of its oflicers or weight of metal, and consequently a smaller employees, in prosecution of work for the charge is required for a given result. Government, or by any other person in the In carrying out my invention I incorpo- United States, Without payment of royalty rate finely-divided metallic aluminum with a 55 thereon. finely-divided oxidizing agent, such as a This invention .relates to a new explosive perchlorate. I prefer potassium perchlocomposition and. more specifically to alumirate for this purpose, although other perchlo-. num ophorite. T rates, such as that of sodium .or ammonium I The term ophorite is applied to a mechanimay be substituted, in whole or in part, for

cal mixture of metallic'magnesium and a the potassium perchlorate. I perchlorate, which on ignition burns rapid- I find that the source and quality of the 1y, yielding intense heat and a suflicient aluminum metal is an important factor in amount of gas for development of highpresthe final properties of the mixture. I have 5 sures when the material is confined. This found that flake aluminum (aluminum foilmaterial is used in connection with military ground in oil) is most satisfactory for my explosives for the fragmentation of shells purpose. Also, the fineness of the perchloand the ignition of amaterial, such as therrate as well as its freedom from impurities mite. and moisture content are important factors Among the objects of this invention is the in the effectiveness of 'the'product. production of an ophorite mixture which pos- A specific example of preparing my com sesses greater effectiveness, power and staposition is as follows: The aluminum metal, bility and which can-be produced from mawhich should be preferably substantially terials of greater availability than the ophopure and ground so that about at least rite previously made.- shall be of -200 mesh and containing not 75 A further object of this invention is the in excess of 2% of oil is added to the potasproduction of an ophorite wherein metallic sium perchlorate, preferably in a; pure and aluminum is substituted for the magnesium dry condition and of a fineness of at least metal of the prior compositions of this charmesh. The components are used approxacter. imately in proportions which will give com- 80 Aluminum ophorite possesses the followplete oxidation of the aluminum metal, the ing-advantages over magnesium ophorite: theoretical proportions by weight, in which 1. Aluminum metal is more available and the aluminum and perchlorate are used, becan be produced more cheaply than metallic mg 34.2% aluminum and 65.8% potassiummagnesium. perchlorate, in which the oil is present w th 2. In magnesium ophorite, the magnesium the aluminum not in excess of 2%, which is employed as coarse cuttings and this afreactaccording to the following equation: fords greater possibil ty of segregatlon of 8A1+3KC1O4:4A12O3+3KO1 the magneslum with consequent failure of the mixture. If finely-divided magnesium The components are mixed separately, and 99 be used to counteractthis tendency toward are then placed in atumble barrel or glass segregation, the resulting mixture becomes bottle wherein they may be shaken and en' too sensitive to handle and the rate of explotirely mixed without heat or frlction. sion is too rapid to ignite the theremite. The The present invention is not limited'to the aluminum in the ophorite is employed in a specific details set'forth in the foregoing exfinely divided condition. amples which should be construed as illus- -3. Aluminum ophorite is more stable in trative'and not byway of limitation, and in storage than'magnesium ophorite. There is view of the numerous modifications which less tendency for surface oxidation in the may be effected therein without departing former than in the latter; I w from the-spirit and scope of this invention,

it is desired that only such limitations be imposed as are indicated in the appended claims.

I claim as my invention:

1. An explosive 'material comprising a 5 mixture of finely ground metallic aluminum foil ground in oil, said oil constituting not in excess of two per cent of the mixture and a perchlorate of an alkali metal.

2. An explosive material comprising a m mixture of metallic aluminum foil finely ground in a mineral oil and potassium perchlorate, said oil constituting not in excess of 2% of the mixture.

a 3. A process for preparing an explosive material comprising mixing finely ground metallic aluminum foil ground in a mineral oil said oil not constituting in excess of two per cent of the mixture and a perchlorate of an alkali metal in proportion for complete oxidization of the aluminum to aluminum oxid by the perchlorate.

4. A process for preparing an explosive material comprising mixing finely ground metallic aluminum foil ground in a mineral oil said oil not constituting in excess of two per cent of the mixture and potassium perchlorate in proportions for complete oxidization of the aluminum to aluminum oxid by the potassium perchlorate.

so 5. An explosive material comprising a mixture of finely divided metallic aluminum ground in oil, said oil constituting not in excess of two per cent of the mixture and potassium-perchlorate, said aluminum being ground so that at least 80% shall be of 100- I. 200 mesh and the potassium-perchlorate of a fineness of at least 150 mesh.

6. Aprocess for preparing an explosive material comprising mixing finely ground 40 metallic aluminum foil, ground in a mineral oil, and finely ground potassium-perchlorate in proportions of approximately 34.2% of aluminum and 65.8% of potassium perchlorate, said mixture not containing in excess of 2% of oil.

' 7 An explosive material. comprising a. mixture of flake aluminum and a perchlorate of an alkali metal.

8. An explosive material comprising a mixture of flake aluminum andpotassiumperchlorate.

-DONALD: B. BRADNER. 

